WASHINGTON DC—In a meeting with Russian foreign minister Sergei Lavrov and ambassador to the US Sergey Kislyakat held at the White House last week, US President Donald Trump revealed highly classified information which is believed to jeopardize a critical source of intelligence on ISIS and relations with an ally that had provided the information, as reported on Monday by The Washington Post.

The information shared with the Russian foreign minister and ambassador had been provided to Trump by an influential US partner. The intelligence was considered so highly sensitive that the details have even been withheld from officials within the US government as well as US allies. The US partner in question had not given the United States permission to release the intelligence details.

The US partner and ally have access to the inner workings of ISIS which could endanger future cooperation between the two nations.

The ally and partner has not been named.

Trump shared the information with Russia regarding a threat that the US had learned by means of espionage capabilities of a key partner. He described the possibility of an attack being plotted by the militant group. The most alarming information was the release of the specific city within ISIS held territory where the US partner revealed the threat.

The Post stated that US officials familiar with the situation are frustrated with Washington’s inability to safeguard sensitive information in relation to Iraq and Syria. “If that partner learned we’d given this to Russia without their knowledge or asking first, that is a blow to that relationship,” the U.S. official said.

“Everyone knows this stream is very sensitive, and the idea of sharing it at this level of granularity with the Russians is troubling,” said a former senior U.S. counter terrorism official who also worked closely with members of the Trump national security team. He and others spoke on the condition of anonymity, citing the sensitivity of the subject as reported by the Post.

US intelligence officials are worried about the specific location being revealed by Trump, since Russia has the means to use this information to identify which US ally or intelligence facilities are involved.

Officials also stated that the information released could potentially be used for other purposes, specifically in regards to Russia’s presence in Syria. If the source of the threat is identified, Russia would have the capability of disrupting the plot if they wished to do so.

Although both the US and Russia regard ISIS as an enemy, they have conflicting views regarding Syria, where military assets and personnel have been deployed to support President Bashar al-Assad by Moscow.

Trump also released the means in which the US is contemplating or has already taken to counter the threat which includes military operations in Iraq and Syria.

Assistant to the president for homeland security and counter terrorism, Thomas P. Bossert immediately placed calls to the directors of the CIA and the NSA attempting to quickly contain potential fallout of the situation. These agencies are most directly involved in the intelligence-sharing arrangement with the US partner.

Trump welcomed Lavrov and Kislyak into the Oval Office just one day after the controversial firing of FBI Director James Comey who was in the midst of an intensive investigation including potential links between the Trump campaign and Russia.

White House officials involved in the meeting defended Trump by saying he only discussed his concerns about terrorism with the foreign minister, not releasing intelligence information.

All US media outlets were barred from attending the meeting in the Oval Office. However, a Russian photographer had taken photos of the session. The photos were later released by the Russian state-run news agency, Tass.

Trump expressed his anger at the release of these photos.

“We were not informed by the Russians that their official photographer was dual-hatted and would be releasing the photographs on the state news agency,” a Trump administration official said, according to the Post.